Did you know that the U.S. flag is flown 24 hours a day, by either presidential proclamation or by law, at these locations:

Fort McHenry, National Monument and Historic Shrine, Baltimore, Maryland
Flag House Square, Baltimore, Maryland
United States Marine Corps Memorial (Iwo Jima), Arlington, Virginia
On the Green of the Town of Lexington, Massachusetts
The White House, Washington, D.C.
United States customs ports of entry
Grounds of the National Memorial Arch in Valley Forge State Park, Valley Forge, Pennsylvania ... See more